Electromagnetic sound reproducer



March 22 1927. 1,621,562

LE ROY W. STAUNTON ELECTROMAGNETIC SOUND REPRODUCER Filed 051:. 16, 1925 TIE. a

' INV ENTIVOIRI. Wmfl ATTORNEY Patented Mar. 22, 1927.

UNITED STATES PATENT OFFICE.

LE ROY w. srmm'ron,

nanom'ronms, me, or NEWARK,

SEY.

OF JACKSON HEIGHTS NEW YORK, ASSIGNOR TO BRANDES NEW JERSEY, CORPORATION OF NEW J'EB- ELECTBOMAGNETIC SOUND BEPRODUCER.

Application filed October 16, 1926. Serial No. 142,056.

My invention relates broadly to electro;

magnetic sound reproducers and more particularly to a loud speaker for radio broadcast reception.

One of the objects of my invention 15 to provide a loud speaker for radio broadcast reproduction in which the entire range of musical notes may be efficiently reproduced.

Another object of my invention is to provide a loud speakersystem having a plurality 'of armatures each having d fi'ermg natural periods, the armatures being arranged to impart vibration to the sound reproducing diaphragm for reproduction of all of the tones over the entire musical scale.

Another object of my invention is to provide a construction of loud speaker having a plurality of armature members each possessing different characteristics for the efficient response to a particular range of tone frequencies with connections to a sound reproducing diaphragm whereby the entire range of musical frequencies may be efficiently reproduced.

Still another object of my invention is to provide an arrangement for loud speakers in which a plurality of drivers are provided for actuation of individual armature members each possessing characteristics which render the cooperation of the driver and armature member extremely efficient over portions of the entire range of musical frequencies the armatures being individually connected with a sound reproducing diaphragrn for delivering the armature vibrations to said diaphragm.

Still another object of my invention is to provide a loud speaker having a relatively large sound reproducing diaphragm wit vibratory members each efliciently responsive to a particular range of tone frequencies connected to different points in said diaphragm, the armature which delivers the lowest register of musical frequencies being connected to substantially the'center of the diaphragm, the armature which is respon sive to the highest register of musical frequencies being connected to a point substantially off of the center of said diaphragm and the armature which is responsive to the middle register of musical notes being connected to a point in said diaphragm intermediate the aforementioned points whereby sectional view taken on line 3-3 of'Fig. 1-

through the loud speaker construction of my invention; Fig. 4 is a modified plan view of the multiple armature construction ofmy invention; and Fig. 5 shows diagrammatically the arrangement of the magnetic driving System in the loud speaker of my invention.

Referring to the drawings in detail reference character 1 designates a casing in which the operating parts of the loud speaker of my invention are mounted. Reference character 2 designates a permanent magnetic system for the loudspeaker of my invention. Laminated pole pieces 3 and 4 have been shown in fixed relation to the casing l and the permanent magnetic system 2 with windings 5 and 6 on the pole pieces 3 and 4. ,In the drawings I have illustrated a continuous Winding on the pole pieces 3 and 4, but I desire that it be understood that separate windings corresponding in number to the'number of driving armatures may be emplo ed as will be hereinafter more fully descri ed.

Located on the top flan e of the casing 1 I provide securing means for step like members 7 and .8 which are arranged at diametrically opposite points of the casing 1. A

plurality of armature members 9, 10 and 11 are provided which for the purpose of illustrating my invention have been shown as three in number. Thearmature members 9, 10 and 11 each possess different natural periods for the efiicient reproduction of musical frequencies over a selected range. For example, armature member 9 responds to the lowest register of musical notes. Armature members 10 responds to the middle register of musical notes, while armature member 11 is responsive to the highest regof musical notes. nrmatures 9, and

11 have different thicknesses so that" in order to secure the armature members in'position member 7 as having 0 set faces 7, 7" and 7 'for clamping the armature members 11, 10 and 9, respectively, in accordance with the thickness thereof.

A. stretched sound reproducing diaphragm 18 may be emplo ed in the loud speake r of my invention. have illustrated the diaphragm 18 as supported by frame members 15 and 16 with securing bolt 17 passing therethrough and into the support- .ing 'members 12 and 14 which are in turn connected with the casin 1. I provide three link members 19, 20 an 21 which interconnect the armatures 9, 10 and 11 at diiferent points-along the diaphragm 18. The link member 19 connects at a point 19 along armature 9 intermediate the pole pieces 3 and 4 of the electromagnetic driver with substantially the center of the sound reproducing diaphragm 18 as illustrated at 19*. Thisarrangement provides for the reproduction of the lowest-register of the musical frequencies by reason of the connection at th; freest point of oscillation for the dia-. P a v .20 1% armature 10 which is ofi-center with respect to the electromagnetic ole pieces 3 n 4 and connects to the diap ragm at 20? which is ofi-center withrespect to the center of diaphragm 18. connection provides for the eflicientreproduction of freuencies lying within the middle register of t e musical notes.

Link 21 connectsat oint 21 on driving armature 11 which is an antially off-center along the armature with respect to the electromagnetic driving pole. pieces 3 and 4,

- link21 terminating at 21" on the diaphragm 18 which-sis substantially off-center for the reproductiopsgof the higher, musical frequencies. a

. As represented in Fig. 4 the armature members'i), 10 and 11 may be in the form of cantilever devices suspended from one side of the, casing 1 by means of the step. like member 7. Q

In Fig. 5 I have illustrated the arrangement of a plurality of magnetic windings 22,

-23 and 24 each of which cooperates with armatures 9, 10 and 11, respectively,,the electromagnetic driver being matched with respect to its cooperating armature for the se curingof maximum efiiciency in the sound re 'roduction.

hile I have described my invention as a plied to a sound reproducingdiaphra m 0 the largedirect' acting disc .type, I esire-that It be understood that my invention is equally applicable to diaphr s of con cal type, or other shapesmgy 18. The link 20 connects at a point .bers'being efliciently res parted to the diaphragm, connections being established as set forth in the drawings. In

order to show the electromagnetic driver and that no limitations upon my invention are intended other than are imposed by the scope of the appended claims.

What I claim as new anddesire tosecure by Letters Patent of the United States is as follows:

1. An electromagnetic sound reproducer comprising an electromagnetic driver, a pluralityof armatures each responsive to differ ent ranges of tone frequencies arranged to be actuated by said driver, a sound reproducing diaphragm of the direct acting'type and independent connections between said armatures and points spaced apart along said diaphragm whereby vibrations over the entire range of musical frequencies may be imparted to said diaphragm.

2. An electromagnetic sound reproducer comprising electromagnetic driving means, a plurality of armature members arranged to be actuated by said electromagnetlc driving means, said armature members being individually responsive to difi'erent ran es of musical frequencies, a sound repro ucing diaphragm of the direct acting type, a connection between one of said armatures and ac'enter point in. said diaphragm and connections between others of said arma- .a plurality of armature members each. re-

sponsive to a different range of musical fre quencies, one of said armature members being efliciently' responsive to the lower register of musical frequencies, another of said armature members being efliciently respon sive to. the higher register of musical frequencies, and another of said armature memponsive to a register of musical frequencies intermediate the frequencies to which said aforementioned 81* mature members are efliciently responsive, a sound reproducing diaphragm of the large directacting type, andconneetions between said armatures and separate points on said sound reproducing diaphragm whereby sound may be reproduced over the entire range of musical notes. 7

4. electromagnetic sound rcproducer compr sing electromagnetic driving means,- a

plurality'of armature members each responsive 'to a difierent range of musical frequencies, one of said armature members being efficiently responsive to the lower register of musical frequencies, another of said armature members being efiiciently responsive to "the higher register of musical frequencies,

and another of said armature members being eficiently responsive to a reglster of:

I register of musical frequencies and the center point of said diaphragm, a connection" between said armature member responsive to the higher register of musical frequencies and a point substantially ofi-center on said diaphragm, and a connection between said armature member responsive to the said intermediate register of musical frequencies and a point on said diaphragm intermediate 'nular flange on said casing,

the hereinbcfore mentioned points of connection whereby notes over the entire range of musical frequencies may be'efliciently reproduced by said diaphragm. A

5. Zia-electromagnetic sound reproduce'r comprising a casing, driver positioned within said casing, an ana plurality of armature members supported by said flange magnetic driver, each of said armature members having 'a different thickness and a step an electromagnetic 'and extending laterally over said electrolike member secured to said flange for maintaining said armature members in positive spacedrelation, phragm of the large direct acting type and connections between separated points on said sound reproducing diaphragm and-separated .points on said armature'members whereby said armature members independently im part vibrations to different parts of said sound reproducing diaphragm.

In testimony whereof I aflix my signature.

LE ROY W. STAUNTON.

a sound reproducing dia-' 

